Presser-foot mechanism



Jan. 28, 1930. F. ASHWORTH 1,744,858

PRESSER FOOT MECHANISM Original Filed May 19 1920 3 Sheets-Sheet 1 Jan. 28, 1930.

F. ASHWORTH PRESSER .FOOT MECHANISM 3 Sheets-Sheet 3 Original Filed May 19, 1920 grim Patented Jan. 28, 1930 UNITED STATES PATENT OFFICE FRED ASHWORTH, 015 BEVERLY, MASSACHUSETTS, ASSIGNOR T UNITED! SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY ]?RESSER-FOOT MECHANISM Original application filed The present invention relates to sewing machines and more particularly to presser foot actuating mechanism for such machines.

The object of the invention is to simplify and improve the construction and mode of operation of sewing machines and part1cularly to provide an'improved constructlon of presser foot actuating mechanism for such machines.

The invention consists in the construction, combinations and arrangements of parts hereinafter described and claimed. 7

The drawings illustrate the invention as embodied in a lock stitch outsole shoe sewing machine, a sufiicient portion of such machine being shown to' enable the invention to be clearly understood.

In the drawings, Fig. 1 is a vertlcal sectional'view of the upper portion of the sew- 2 ing machine; Fig. 2 is a sectional view on line 2-2 of Fig. 1; Fig. 3 is a vertical sectional view of a portion of the presser foot actuating mechanism with parts shown in the positions that they assume when the needle 1s at the limit of its loop drawing stroke; Fig. 4 is'a similar view of the presser foot actuating mechanism with the parts shown in the posltion they assume immediately after the needle has reached the limit of its work piercing stroke; and Fig. 5 is a left side elevation of the head of the machine.

The lock stitch outsole sewing machine, a portion of which is illustrated in the drawings, is provided with the stitch forming mechanism including a curved hook needle 6 and curved awl 8, and also with the work support 10 and presser foot. 12 disclosed 1n my copending application, Ser. No..382,558, filed May 19, 1920, of which the present application is a division. In the operation of such sewing machines, the work 1s fed by means of the work support and presser foot while. the needle and awl are out of the work. At the completion of the feeding operation the awl is actuated to pierce the work and as the awl retracts the needle closely follows the awl'through the work. During the feeding operation and during the described movements of the awl and needle, the work is firm-v ly clamped on the work support by the presser May 19, 1920, Serial No. 382,558. Divided and this application filed November 23, 1923. Serial No. 676,538. Renewed April 24, 1929.

foot. At the limit of the work piercing stroke of the needle, the pressure of the presser foot on the work is relieved and the presser foot and work support are returned to their initial position, whereupon the presser foot is again oausedto clamp the work firmly the work support.

During the action of the stitch forming devices in forming a stitch, and during the feeding operation, the pressure foot 12 is locked in clamping engagement with the work so that the work is tightly clamped between the presser foot and work support. At the end of the feeding op,eration,'however, the presser foot is unlocked "and" is caused to lightly engage the work by. means of a coiled spring 20 connected with the rear end of the presser foot lever 22 so that the presser foot will offer practically no re-,

sistance to the back feeding or retracting movement of the work support and presser foot. At the end of the retracting movement 'of these parts, the presser foot is pressed into engagement with the work with a comparatively heavy pressure so as to clamp the stock firmly against the work support and is then looked in position. The presser foot remains locked until the end of the feeding operation when it is again unlocked and the cycle of operationsrepeated. I

The locking mechanism for the presser foot comprises a wedge block 26 (Figs. 1 and 2) the upper end of which engages the rear end of the presser foot lever. faces of the wedge block 26 are preferably arranged at a relatively small acute angle to each other, as shown in Fig. 1. A guide plate 28 secured to the frame is arranged to The lateral engage the forward face of the wedge block and acts to limit the movement of the wedge block laterally in one direction. A longitudiresser foot upon the work. The block is thus moved upwardly by means of an arm 34, the forward end of which is bifurcated and is provided with studs or rolls 36 that engage horizontal slots 38 in opposite sides of the block. The arm 34 is secured to a rock shaft 40 which is urged in a direction to move the locking wedge block 30 upwardlyby means of a spring 48 coiled about the shaft and having one end connected to the arm 84 and its other end connected to the frame of the machine.

T he presser foot is unlocked when the needle has reached the limit of its work piercing stroke, preliminary to the back feeding of the Work support and presser foot, by mechanism connecting the rock shaft 40 with the needle actuating mechanism. This mechanism comprises a friction disk 52 (Figs. 3 and 4) secured to the left end of the rock shaft 40, the periphery of which is adapted to be engaged by a friction shoe 54 to turn the rock shaft in the direction to lower the locking wedge block 30 in opposition to the torsion spring 48. The shoe comprises a link having one end pivoted on a pin 58 extending between the arms of a yoke 60, the lower ends of the arms being joined by a bar 62 and the upper ends of the arms being loosely mounted on the rock shaft 40 at opposite sides of the disk 52. The other end of the shoe 54 is pivotally connected with one end of a link 64 and the other end of the link 64 is pivotally connected with the free end of an arm 66 projecting from a rocking sleeve 68 mounted on a shaft or rod 70 secured to the frame, the rocking sleeve forming a part of the needle actuating mechanism.

The friction shoe 54 is normally maintained in a certain position relatively to the cross bar 62 by means of a spring pressed plunger 72 mounted in a longitudinal aperture in the friction shoe and engaging the cross bar 62, the plunger acting to maintain a stop lug 74 formed on the lower end of the friction shoe in engagement with the cross bar. \Vhen the needle is at the limit of its loo drawing movement, the friction shoe 54 an( the link 64 are substantially in alinement, as shown in Fig. 3. During the work piercing stroke of the needle, the rocking sleeve 68 acts to swing the yoke 60 downwardly, the friction shoe being maintained by the plunger 72 in its normal position relatively to the cross bar 62 until the cross bar engages a yielding stop 76. The continued movement of the link 64 after the engagement of the cross bar 62 with the yielding stop 76 cooperates with the stop to turn the friction shoe about the pivot pin 58 against the action of the spring pressed plunger 72. This turning movement of the friction shoe brings an eccentric friction surface 80 formed on the shoe into engagement with the periphery of the disk 52, whereupon the continued movement of the link 64 acts through this engagement of the friction shoe with the friction disk to turn the shaft 40 in the direction to unlock the presser foot, which occurs near the limit of the work piercing stroke of the needle.

At the start of the loop drawing stroke of the needle, the rocking sleeve 68 is turned in the direction to swing the yoke 60 rearwardly out of engagement with the yielding stop 7 6, thereby permitting the friction shoe 54 to resume its normal position relatively to the cross bar 62 and out of engagement with the friction disk 52 to permit the presser foot to again clamp the work onthe work support.

The yielding stop 7 6 comprises a plunger rod 82 (Fig. 3) mounted to slide in an aperture in the frame and is urged rearwardly by means of a spring 84 coiled about the rod and engaging a shoulder on the red, the rearward movement of the rod being limited by adjustable stop nuts 86 threaded on the forward end thereof.

The needle actuating mechanism comprises a link 88 connecting the needle segment with an arm 90 projecting from the locking sleeve 68 that actuates the mechanism for unlocking the presser foot as hereinbefore described. The arm 90, the sleeve 68, and an arm 92 projecting from the sleeve constitutes a bell crank. The arm 92 of the bell crank is connected by a link 94 with one arm of a lever 96 pivotally mounted on a pin 98 secured to the machine frame. The other arm of the lever 96 is connected by a link 100 with an actuating crank 102 on a driving shaft 104.

Having thus described the invention what is claimed is 1. A sewing machine having, in combination, a work support, a lever, a presser foot mounted on one end of the lover, a wedge block engaging the other end of the lever, a vertical rod, a locking wedge block engaging the first wedge block mounted to slide on the rod, and means for sliding the locking wedge block on the rod to lock and unlock the presser foot.

2. A sewing machine having, in combination, a driving shaft, a needle, needle actuating connections between the driving shaft and needle, a work support, a presser foot, a wedge block connected with the presser foot, a second wedge block cooperating with the first wedge block when moved in one direction to lock the prcsser foot and when moved in the opposite direction to release the presser foot, and connections between the second wedge block and said needle actuating connections to move the second wedge block in one of said directions.

3. A sewing machine having, in combination, stitch forming devices including a needle, needle actuating'mechanism, a work sup port, a presser foot, a wedge block connected with the presser foot, a locking, wedge block for engaging the first wedge block, and means for moving the locking wedg'e block to lock and unlock the presser foot comprising a shaft, connections between the shaft and the locking wedge block, means for turning the shaft in a direction to lock the presser foot, and connections between the shaft and the needle actuating mechanism for turning the shaft in the opposite direction to unlock the presser foot.

i. A sewing machine having, incombination, stitch formingdevices including aneedle, needle actuating mechanism, a work support, a presser foot, a wedge block connected with the presser foot, a locking wedge block for engaging the first Wedge block, and means for moving the locking wedge block to'lock and unlock the presser foot comprising a shaft, connections between the shaft and the locking wedge block, means for turning the shaft in a diroctionto lock the presser foot, and means for turning the shaft in the opposite direction to unlock the presser foot comprising a disk secured to the shaft, and an oscillating gripping device acting on the periphery of the disk.

5. A sewing machine having, in combination, stitch forming devices including a needle, needle actuating mechanism, a work support, a presser foot, a Wedge block connected with the presser foot, a locking wedge block for engaging the first wedge block, and

means for moving the locking wedge block to lock and unlock the presser foot comprising a shaft, connections between the shaft and the locking wedge block, means for turning the shaft in a direction to lock the presser foot, and connections between the shaft and the needle actuating mechanism for turning the shaft in the opposite direction to unlock the presser foot at the limit of the work piercing stroke of the needle.

6. A sewing machine having, in combination, stitch forming devices including a needle, needle actuating mechanism, a work support, a presser foot, a wedge block connected with the presser foot, a locking wedge block for engaging the first wedge block, and means for moving the locking Wedge block to lock and unlock the presser foot comprising a shaft, connections between the shaft and the locking wedge block, means for turning the shaft in a direction to lock the presser foot, and means for turning the shaft in the oppo site direction to unlock the presser foot comprising an oscillating arm, and means acting to operatively connect the arm and shaft during the latter portion of the movement of the arm in one direction.

7 A sewing machine having, in combination, stitch forming devices including a needle, needle actuating mechanism, a Work suprisin an oscillatim arm and means actin Y b 7 to operatively connect the arm and shaft during the latter portion of the movement of the arm in one direction and to disconnect the i arm and shaft substantially at the start of the movement of the arm in the opposite direction.

8. A sewing machine having, in combination, a work support, a presser foot, means for locking and unlocking the presserfoot comprising a shaft, connections between the shaft and presser foot to lock the presser foot when the shaft is turned in one direction and to unlock the presser foot when the shaft is turned in the opposite direction, means for turning the shaft in the direction to lockthe presser foot, and means for turning the shaft in thedirection to unlock the presser foot comprising adisk carried by the shaft, an oscillating arm, a gripping deviceto act on the disk connected to the arm, and means cooperating with the arm to cause the gripping device to operatively engage the disk during the latter part of an oscillation of the arm in'one direction.

9. A sewingmachine having, in combina tion, stitch forming devices including a needle, needle actuating mechanism, a work support, a presser foot, means 'for locking and unlocking the presser foot comprising a shaft, connections between the shaft and the presser foot to lock the presser foot when the shaft is turned in one direction and to unlock the presser foot when the shaft is turned in the opposite direction, means for turning the shaft in the direction to lock the presser foot, and means for turning the shaft in the oppo: site direction to unlock the presser foot come prisingan oscillating arm, and means acting to operatively connect the arm and shaft during the latter portion of the movement of the arm in one direction. 7

10. A sewing machine having, in combi-, nation, stitch forming devices including a needle, needle actuating mechanism, a work support, a presser foot, means for locking and unlocking the presser foot comprising a shaft, connections between the shaft and presser foot for locking the presser foot when the shaft is turned in one direction and for unlocking the presser foot when the shaft is turned'in the opposite direction, means for turning the shaft in the direction to lock the presser foot,and means for turning the shaft in theoppositedirection comprising an oscilluting arm, and means acting to operatively connect the arm and shaft during the latter portion of the movement of the arm in one direction and to disconnect the arm and shaft during the movement of the arm in the opposite direction.

11. A sewing machine having, in combination, a Work support, a presser foot, means for locking and unlocking the presser foot comprising a shaft, connections hetveen the shaft and presser foot to lock the presser foot when the shaft is turned in one direction and to unlock the presser foot when the shaft is turned in the opposite direction, means for turning the shaft in the direction to lea-k the presser foot, means for turning the shaft in the direction to unlock the presscr foot comprising an oscillating arm. a gripping device for connecting and disconnecting the arm and shaft, and means cooperating with the arm to cause the gripping device to connect the arm and shaft during the latter part of the movement of the arm in one direction and to disconnect the arm and shaft dnring the movement of the arm in the opposite direction.

12. A sewing machine having, in combination, a Work support, a presser foot, means for locking and unlocking the presscr foot comprising a shaft, connections between the shaft and presser foot to lock the presser feet when the shaft is turned in one direction and to unlock the presser foot when the shaft is turned in the opposite direction. means for turning the shaft in the direction to lock the presser foot, and means for turning the shaft in the direction to unlock the presser foot comprising a disk carried by the shaft, a gripping device to act on the disk, a coni tinuously rotating crank, connections between the gripping device and the crank, and means cooperating with the crank to cause the gripping device to operatively engage the disk during a predetermined number of degrees of rotation of the crank.

13. A sewing machine having, in combination, a work support, a presser foot, means for locking and unlocking the prcsscr foot comprising a shaft, connections between the shaft and presser foot to lock the presser foot when the shaft is turned in one direction, and to unlock the presser foot When the shaft is turned in the opposite direction, means for turning the shaft in the direction to lock the resseur foot, and means for turning the sha in the direction to unlock the presser foot comprising a disk carried by the shaft, a friction shoe adapted to act on the periphery of the disk movable bodily about the axis of the disk, and means for thus moving the friction shoe and for causing the friction shoe to engage the periphery of the disk during a portion of such movement thereof to look the disk and friction shoe together.

14?. A sewing machine having, in combination, stitch forming devices including a curved hook needle, a work support, a presser foot, means for locking and unlocking the presser foot, a continuously rotating crank, and means actuated by the crank for controlling the operation of said locking and unlocking means for the presser foot.

15. A sewing machine having, in combination, stitch forming de ices including a curved hook needle, :1 work support, a presser foot, means for locking and unlocking the presser foot, a continuously rotating crank, and means actuated by the crank for actuating the needle and for controlling the operation of said locking and unlocking means for the presser foot.

FRED ASHVVORTH. 

